1. Field of the Invention
The present invention relates to a communication method and a communication system which are suitable for being applied to a digital video/audio input/output interface standard called the HDMI (High-Definition Multimedia Interface) standard and relates to a transmission method, a transmission apparatus, a receiving method and a receiving apparatus which are applied to the communication system. Particularly, the present invention relates to technology for transmitting video data for three-dimensional display using the digital video/audio input/output interface standard.
2. Description of the Related Art
Lately, the HDMI standard has been developed as an interface standard to transmit uncompressed digital video data and the like between a plurality of video apparatuses. According to the HDMI standard, video data is transmitted as individual primary color data respectively transmitted by one pixel. In the HDMI standard, audio data is also transmitted using a transmission line for the video data in a blanking period of the video data. Additive primary color data of three channels that are red, green and blue (R-data, G-data, and B-data) are transmitted as the primary color data. Luminance and color-difference signals such as Y, Cb and Cr may be transmitted instead of the primary color data.
According to the HDMI standard, one pixel data of respective colors is basically transmitted by 8 bits. Synchronization signals such as a horizontal synchronization signal and a vertical synchronization signal are also transmitted at a timing that each synchronization signal is arranged. A video data transmission line using pixel clock and a control data transmission line are provided.
FIG. 1 is a schematic diagram showing an example of the case in which the primary color data (R-data, G-data and B-data) are transmitted using an interface of the HDMI standard. Three channels of channel 0, channel 1 and channel 2 are provided to video data, and the R-data, G-data and B-data are individually transmitted. FIG. 1 shows an example of a period for transmitting data composed of four pixels of pixel 0, pixel 1, pixel 2 and pixel 3, and one pixel data in each channel includes 8 bits.
More specifically, the channel 0 is used for the B-data (blue data) and B0 data of 8 bits is transmitted during a period of the pixel 0, and subsequently B1 data, B2 data and B3 data of 8 bits are sequentially transmitted in sync with the pixel clock (not illustrated). The channel 1 is used for the G-data (green data) and G0 data of 8 bits is transmitted during the period of the pixel 0, and subsequently G1 data, G2 data and G3 data of 8 bits are sequentially transmitted in sync with the pixel clock. The channel 2 is used for the R-data (red data) and R0 data of 8 bits is transmitted during the period of the pixel 0, and subsequently R1 data, R2 data and R3 data of 8 bits are sequentially transmitted in sync with the pixel clock.
Although not illustrated in FIG. 1, the control data and the pixel clock are transmitted using other channels according to the interface of the HDMI standard. The control data can be transmitted from a video data transmission device (source device) to a video data receiving device (sink device), and can also be transmitted from the receiving device (sink device) to the transmission device (source device). Further, data is encoded by 8 bits in the source device, and the encoded data is decoded by 8 bits in the sink device.
As described above, one pixel is transmitted by 8 bits per color according to the interface of the HDMI standard.
WO2002/078336 discloses details of the HDMI standard.